Milkwood Trees
Why is our forest special?
Grootbos Nature Reserve derives its name from our Milkwood forest, the “Groot bos”, which means the big thicket. It is one of only ten Milkwood forests of its type in the world – all of which are restricted to the Stanford-Gansbaai area, of which only four are formally protected on the Grootbos Nature Reserve. This complex of Milkwood thickets include the largest of the south-western Cape’s lowland dune thickets. Botanically it is relatively species poor. Only 40 species have been recorded in the Milkwood forest. The levels of calcium in the soil of the forest are very much higher than elsewhere in the reserve. Thicket soils have been found to be the most fertile on the Agulhas Plain, due in part to plant-induced organic enrichment. The Grootbos forest is approximately 22 hectares in extent and contains trees that are many hundreds of years old. The forest is also home to at least 34 bird species and a variety of mammals including porcupine, honey badger, bushbuck and mongoose. At Grootbos some individual Milkwoods are estimated to be over 800 years old. The conservation of the Grootbos forest is particularly important as it is the only forest of its type growing in a protected area.
In the past, a lack of large trees in the Cape’s fynbos led to heavy demands being made on Milkwood timber. It has hard and very durable wood and was used for building boats, bridges, and mills, making furniture and for firewood. The Grootbos forest used to be situated on the main road from Stanford to Gansbaai and other inland villages. The large trees in our forest would have been highly sought after as a timber resource. When the Lutzeyer’s purchased Grootbos in 1991, the then owner was still making use of the forest trees for timber and firewood. However, woodcutting was not the only form of human impact on the forest. During the 1950’s the government's Department of Forestry planted Australian Acacias on the shifting dunes that used to occur between the forest and the sea. These trees are extremely fast growing, are dispersed by birds and rapidly spread to the forest boundary, from where they infiltrated disturbed patches within the forest. During bush fires these Acacias burn fiercely and kill adjacent Milkwoods due to the intensity of heat they generate. Thick alien growth also prevented the germination of Milkwood seed and the growth of seedlings in the forest.
By comparing aerial photographs of the forest in 1938 with 1989 it was evident that these human impacts have resulted in at least an 18% reduction in the size of the forest.
The White Milkwood (Sideroxylon inerme) – the emblem of Grootbos Nature Reserve
The White Milkwood (Sideroxylon inerme) is an evergreen tree that grows along the East Coast of Africa from the Cape Peninsula to the tropics. The species is adapted to withstand harsh, salt laden winds and is generally found in dune sands near the coast. Depending on environmental conditions, their shape and height varies from very short bushes (less than 1 meter) to beautiful umbrella shaped trees of greater than 10m. Milkwoods are slow growers and can live for hundreds of years. Each Milkwood is an ecosystem of its own, providing shelter and food for a variety of animals including birds, insects and tree snakes. Their bark is often clothed with a variety of lichens and mosses, while creepers use their trunks to reach the sunlight. The small white flowers produce a strong odor during summer, which attract insects, while their ripe purple berries are sought after by baboons and forest birds.
Sideroxylon inerme is protected in South Africa where three specimens have been proclaimed national monuments:
1. The Post office tree in Mossel Bay. In 1500, passing Portuguese sailors tied a shoe containing a letter describing the drowning at sea of the famous explorer, Bartholomew Diaz. Over a year later Commander Joao da Nova to whom it had been addressed discovered the message.
2. The treaty tree in Woodstock, Cape Town, next to which stood the small house where the commander of local defenses formally handed over the Cape to the British after the battle of Blaawberg in 1806.
3. The Fingo Milkwood tree near Peddie in the Eastern Cape. In 1835 the Fingo people affirmed their loyalty to God and the British king after English soldiers had led them to safety when they were relentlessly pursued by chief Hintza and his warriors.
Why Milkwood?
The name 'White Milkwood' is derived from the white, milky latex that young branches exude upon breaking.
What was the tree used for?
The wood is heavy, hard, strong and durable, even in damp conditions. Historically it was used as a general-purpose timber, for building boats, bridges and mills. In African medicine a preparation is made from a mixture of oil yielded by the seeds of Trichilia emetica and the roasted powdered roots of Sideroxylon inerme; this is rubbed into incisions over a fractured limb to aid healing. An infusion of the bark is reputed to dispel nightmares.
The Future Trees Programme
This programme aims to restore the forest to its original size of the 1930’s by replanting approximately 10 000-Milkwood seedlings over the next ten years. The first phase of the restoration program required the removal of all alien trees from the forest and its surrounds. This has already been successfully completed. We are now propagating Milkwoods in our nursery for re-establishment into selected planting sites. These sites have been carefully selected to cover the areas where the forest no longer occurs. Guests can become involved by sponsoring a tree and thereby become a patron to the program. The donation is used to cover the expense of propagating, planting and maintaining a Milkwood for the ten-year period of the program. All donors’ names are recorded in the donor’s catalogue and they are sent a yearly newsletter updating them on the growth of their tree and on the overall progress of the project. Read more about the Future Trees Project.
